System for withdrawing body fluid

ABSTRACT

The invention relates to a system for withdrawing body fluid from a body part via a withdrawal site located on the surface of the body part, with at least one sensor for detecting at least one variable dependent on the location or state of the withdrawal site, and with an evaluation unit for evaluating the at least one variable detected by the at least one sensor and for triggering a reaction, dependent on the value of the detected variable, in the system for withdrawing body fluid, said reaction serving to prepare the system for puncturing the surface of the body part, and with at least one puncturing device for creating an opening in the body at the withdrawal site. The invention further relates to an integrated analysis system, to a method for configuring a system for withdrawal of body fluid, and to a method for selecting a menu item from a menu for controlling a system for withdrawing body fluid from a body part.

REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation of PCT Patent Application No.PCT/EP2004/007409, filed Jul. 7, 2004 which claims priority to GermanPatent Application No. 103 32 283.3, filed Jul. 16, 2003, both of whichare hereby incorporated by reference in their entirety.

TECHNICAL FIELD

The present invention relates to a system for withdrawing body fluidfrom a body part, to an integrated analysis system for analyzing thebody fluid, and to a method for configuring a withdrawal device which isused to withdraw body fluid from a body part.

BACKGROUND

Body fluids are mainly withdrawn for the purpose of subsequent analysis,in order to permit diagnosis of diseases or to monitor a patient'smetabolism. This kind of withdrawal is carried out on diabetics inparticular, in order to determine the blood sugar concentration.

In the prior art, blood sampling systems have for some time been knownwith which the patient or hospital staff can withdraw fluid in a simplemanner. An example of an appliance suitable for this purpose is thecommercially available Softclix lancing device, whose operation isdescribed in U.S. Pat. No. Re. 35,803. This appliance provides apossibility of setting the depth of insertion of a lancet into thetissue. Thus, the patient is able to select the minimum depth ofinsertion with which he obtains just the right amount of blood forsubsequent analysis, and he can thus minimize the pain caused bypuncturing the skin. After the patient has created an opening in theskin by puncturing it, then, particularly in the case of shallowinsertion depths, he has to rub or apply pressure to the finger in orderto extract sufficient blood from the puncture wound.

A further system for withdrawing body fluid is known from U.S. Pat. No.5,857,983. This system comprises a hollow puncturing element forcreating an incision at the withdrawal site, and a collection tube whichcommunicates with the puncturing element. A so-called stimulator incitesflow of body fluid from the puncture by compressing a ring of bodytissue around the puncture. During this process, the puncturing elementis moved within the incision by means of a movement mechanism in orderto keep the incision open during withdrawal of the body fluid. A suctionmechanism sucks the body fluid through the puncturing element into thecollection tube. In this appliance too, it is possible to set the depthof insertion of the puncturing element.

U.S. Pat. No. 5,951,492 relates to a further system for withdrawing bodyfluid. It comprises a mechanism for creating a puncture in the skin ofthe user, and a sample-withdrawing element in order to convey the bodyfluid through the puncture and via a capillary element onto a teststrip, which receives the body fluid from the capillary element. Thissystem also comprises a sample-identifying mechanism which detects adroplet of body fluid on the surface of the user's skin.

U.S. Pat. No. 6,319,210 relates to another system for withdrawing bodyfluid, in particular blood or interstitial fluid. This documentdescribes a puncturing mechanism which is also intended to be suitablefor withdrawal sites other than the finger pad. Here once again, astimulator is used to incite the body fluid to flow from an incision,the stimulator either being heated or vibrated.

PCT Patent Publication No. WO 01/89383 discloses a system forwithdrawing body fluid from an area of a body part, in particular thefinger pad, with a compression unit onto which the body part is pressedin a primary direction and which converts the pressure partially into amovement in a secondary direction, partially transverse to the primarydirection, so that the internal pressure in an area of the body part isincreased. This system further comprises a puncturing device, inparticular a lancet or cannula, for creating an opening in the body inthe area of increased internal pressure, the compression unit having apress-on area made of a deformable material.

However, the systems from the prior art are not able to detect thewithdrawal conditions, in particular the location of the withdrawal andthe state of the skin at the withdrawal site, nor are they able toadjust automatically to these withdrawal conditions in order to ensurethat body fluid can be withdrawn as painlessly as possible and in asshort a time as possible, with the fewest possible maneuvers by theuser.

Different withdrawal sites (for example finger pad or forearm) requiredifferent parameter sets for withdrawal of the body fluid and also forits analysis. The volume of blood attainable from the forearm is verymuch smaller. Furthermore, the puncture needed is much deeper comparedto when collecting a sample from the finger. At the same time, there isless need for precise control of the puncture depth, because the overallsensitivity to pain is lower and is influenced less by the puncturedepth. If the parameter set for withdrawal of blood from the forearm wasapplied for withdrawing blood from the finger pad, this would involve anextremely deep and thus very painful incision. Further disadvantages areof a hygienic nature, because incorrect use of the forearm punctureparameters leads to far too great a sample volume, as a result of whichthe system may be soiled.

Moreover, the parameter sets ought to be adapted to the state of theskin at the withdrawal site, for example to the skin temperature.Generally, the warmer the skin, the better its blood circulation, andthe easier it is to collect blood from it.

For substantially pain-free withdrawal of body fluid, it is alsoimportant that this is done only when the withdrawal site is lyingcorrectly on the withdrawal system, that is to say with sufficientpressure and over a sufficiently large surface area.

It is therefore an object of the present invention to make available asystem and a method for withdrawing body fluid, which system and methodavoid the aforementioned disadvantages of the prior art and permitsubstantially painless withdrawal of body fluid in a short space of timeand with the fewest possible maneuvers by the user. They are alsointended to permit withdrawal of body fluid at different withdrawalsites (alternate site testing) and with different states of thewithdrawal site, the system being intended to automatically adjust tothe withdrawal conditions.

SUMMARY

According to the present invention, a system is provided for withdrawingbody fluid from a body part via a withdrawal site located on the surfaceof the body part, with at least one sensor for detecting at least onevariable dependent on the location or state of the withdrawal site, andwith an evaluation unit for evaluating the at least one variabledetected by the at least one sensor and for triggering a reaction,dependent on the value of the detected variable, in the system forwithdrawing body fluid, said reaction serving to prepare the system forpuncturing the surface of the body part, and with at least onepuncturing device for creating an opening in the body at the withdrawalsite.

These and other features and advantages of the present invention will bemore fully understood from the following detailed description of theinvention taken together with the accompanying claims. It is noted thatthe scope of the claims is definitely by the recitations therein and notby the specific discussion of the features and advantages set forth inthe present description.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of the embodiments of the presentinvention can be best understood when read in conjunction with thefollowing drawing in which:

FIG. 1 is a diagrammatic representation of a press-on area in a systemfor withdrawing body fluid, with sensors contained therein.

Skilled artisans appreciate that elements in the figures are illustratedfor simplicity and clarity and have not necessarily been drawn to scale.For example, the dimensions of some of the elements in the FIGURE may beexaggerated relative to other elements to help improve understanding ofthe embodiment(s) of the present invention.

In order that the invention may be more readily understood, reference ismade to the following examples, which are intended to illustrate theinvention, but not limit the scope thereof.

DETAILED DESCRIPTION

The following description of the preferred embodiment is merelyexemplary in nature and is in no way intended to limit the invention orits application or uses.

FIG. 1 shows a cone-shaped press-on area 1 with a circular opening 2arranged at the center. During withdrawal of the body fluid, thepress-on area 1 is pressed onto the corresponding body part via aring-shaped part 3 surrounding the opening 2 and arranged on the topface of the cone-shaped press-on area 1. A puncturing device (not shown)is guided through the opening 2 (perpendicular to the plane of thedrawing) towards the body surface. In the preferred embodiment of thepresent invention illustrated in FIG. 1, the ring-shaped part 3comprises sensors 4 which lie on the body surface during the withdrawalprocedure and concentrically surround the withdrawal site. These aresensors for detecting at least one variable dependent on the locationand state of the withdrawal site, and can be used in the systemaccording to the invention for withdrawing body fluid, or formeasurement in the method according to the invention for configuringsuch a system. For example, the sensors 4 can be electrodes which can beused for measuring the temperature, the electrical resistance, theelectrical conductivity, the electrical current strength or theelectrical voltage. The sensors are connected to electrical leads, glassfibers or similar 5. These can be arranged in a spiral formation in thecone-shaped press-on area 1 so that they can effectively take up thepressure loads repeatedly arising during the withdrawal procedure. Toproduce such a press-on area 1 with sensors 4, the sensors 4 can, forexample, be fitted in a molding tool and encapsulated by an in-flowingplastic. On the surfaces via which the sensors are fitted in the moldingtool, they remain free of plastic and are consequently freely accessibleto the user on the top face of the ring-shaped part 3 of the press-onarea 1. The preferred material of the sensors is dependent on theapplication. A PT 100 sensor, for example, can be used for measuring thetemperature.

The system for withdrawing body fluid can be used simply to create anopening in the body through which the body fluid can flow. However, itcan also comprise other mechanisms which serve to collect the bodyfluid, in particular mechanisms for inciting the body fluid to flow outof the body opening and mechanisms for applying the body fluid onto atest element, on which it is subsequently analyzed. In general, analysissystems designed for the private user operate with disposable testelements which, after coming into contact with a sample of fluid, emit asignal as a function of the analyte concentration. In the field of bloodsugar measurement, optical test elements can be used, in which thereaction of glucose with a test chemical leads to a color change.Electrochemical test elements can also be used, in which an enzymaticconversion of glucose permits amperometric or potentiometric analysis.The test elements can advantageously be designed so that they take upbody fluid actively (for example via a capillary opening).

According to the invention, the system for withdrawing body fluidcomprises at least one sensor. The latter detects at least one variabledependent on the location and state of the withdrawal site. Thewithdrawal site is the location on the surface of the body part at whichthe body fluid, upon withdrawal, flows through an opening in the body.An evaluation unit evaluates the detected variable. For example, itcalculates other variables dependent on this variable and relevant tothe necessary withdrawal parameters. It then triggers a reaction,dependent on the value of the detected variable, in the system forwithdrawing body fluid, in particular the selection and use of a definedparameter set for carrying out the withdrawal of body fluid, the systempreferably having a large number of user-specific parameter sets, fromwhich one is assigned to the value measured with the sensor. The aim ofthe triggered reaction is to ensure that the system for withdrawing bodyfluid has a configuration that is optimized for the withdrawal of bodyfluid. It prepares the system for optimal puncturing of the surface ofthe body part before the puncturing device is activated. In the priorart, the use of sensors in blood-sampling devices is known, for examplefrom PCT Patent Publication Nos. WO 02/101343 A2, WO 02/100251 A2 and WO02/100254 A2. However, these sensors are not used to prepare the devicefor the puncturing and withdrawal procedure to be performed, and insteadthey detect various parameters during the sampling procedure andautomatically trigger the puncturing.

According to the invention, at least one puncturing device serves tocreate an opening in the body at the withdrawal site. Such a puncturingdevice can be a lancet or cannula, as are known in the prior art.Lancets usually have a metal needle, one end of which is ground to apoint. The rear part of the lancet needle remote from the tip is usuallyenclosed by a lancet body made of plastic. Such lancets are known forexample from U.S. Pat. No. 3,358,689.

In the case of a lancet, the latter is preferably removed completelyfrom the tissue after the puncture, so that the puncture site from whichthe body fluid flows is accessible. In the case of a cannula, the lattercan remain at the maximum depth of insertion, in order to convey bodyfluid from this depth, or alternatively it can be drawn back as far asthe surface of the skin in order to collect fluid from there. It is alsopossible to draw the cannula back only partially, so that the puncturechannel is partially freed but the cannula remains in the skin. In thisway, on the one hand, the fluid is better able to flow out of theexposed puncture channel, and, on the other hand, it is not necessary toposition the cannula on the body surface.

The sensor included in the system according to the invention forwithdrawal of body fluid is preferably a sensor for detecting at leastone of the variables of temperature, electrical resistance, electricalconductivity, electrical current strength, electrical voltage, position,inclination, pressure, acceleration, and optical variables.

For temperature measurement, the temperature dependency of electricalresistance materials with positive or negative temperature coefficientsis used, for example, the temperature sensor being designed as a contactthermometer. However, a sensor is also conceivable which measures,without contact, the infrared radiation emanating from the body part inthe area of the withdrawal site. For example, the measurement site isimaged onto a radiation-sensitive element which thus warms up inrelation to its surroundings. This small temperature difference can bemeasured by thermo-elements.

A sensor for measuring electrical resistance and a sensor for measuringelectrical conductivity comprises, for example, electrodes connected toa Wheatstone bridge.

Sensors for measuring electrical current strength or electrical voltagecan contain electrodes connected to an ammeter or to a voltmeter.

Sensors for detecting position or inclination can, for example, bemercury switches.

The pressure measurement by means of pressure sensors is effecteddirectly, via membrane deformation, or by a force sensor. Known types ofpressure sensors are, for example, thick-film or semiconductor pressuresensors or piezoelectric sensors.

Acceleration sensors known in the prior art are, inter alia, Hallacceleration sensors containing a Hall-effect sensor, piezoelectricsensors, or capacitive silicon acceleration sensors.

Sensors for detecting optical variables encompass sensors designed forany type of optical variable, including fiber-optic sensors fordifferent variables, for example for measuring reflected electromagneticradiation.

In a preferred embodiment of the present invention, the sensor is atemperature sensor for detecting the skin temperature on the surface ofthe body part at the withdrawal site. An important parameter forsuccessful blood sampling is skin temperature. Generally, the warmer theskin, the better the blood circulation, and the easier it is to collectblood. Conversely, blood sampling is very difficult at very low skintemperatures. This means that it is expedient to check the temperaturenear the withdrawal site, for example so that the appliance emits awarning if the skin is too cold. Moreover, withdrawal parameters such aspuncture depth and duration of the withdrawal procedure can be adaptedto the actual skin temperature. The temperature sensor for detecting theskin temperature should be able to detect the temperature as close aspossible to the withdrawal site.

In a further embodiment of the present invention, the sensor is a sensorfor detecting the electrical resistance or the electrical conductivityof the skin on the surface of the body part at the withdrawal site. Bydetecting the skin resistance or conductivity, it is possible, forexample, to determine whether there is sufficient contact between thebody part, from which the body fluid is to be withdrawn, and the systemfor withdrawing body fluid, or whether, for example, the user has movedhis finger away between the puncturing procedure and the blood-samplingprocedure. It is also conceivable that, by measuring the skin resistanceor conductivity, the system for withdrawing body fluid can determinewhether the user is using the appliance on the finger or on other bodyparts and can select the appropriate parameters.

In a further preferred embodiment of the present invention, the sensoris a position or inclination sensor for detecting the position orinclination of the system upon contact with the withdrawal site. Thesensor for detecting the position or inclination can be used toautomatically identify the manner in which the user is holding theappliance and, from this, can deduce the intended withdrawal site (forexample finger pad, earlobe or forearm). In the case of withdrawal ofbody fluid from the forearm, the measurement system must be able to copewith extremely small sample volumes. In this case, a preferredorientation of the appliance is one in which the sample is collected inthe direction of the force of gravity (ABA—Automatic Blood Application)since in this way the best yield can be achieved. In the case ofwithdrawal from the finger pad in the direction of the force of gravity,there is a risk of soiling the appliance with too large a sample volume.Consequently, in the case of withdrawal of body fluid from the fingerpad, the preferred orientation of the appliance is counter to the forceof gravity. Therefore, from the position or inclination of theappliance, it is possible to draw conclusions concerning the intendedwithdrawal site.

In a further embodiment of the present invention, the sensor is apressure sensor for detecting the pressure with which a press-on area ofthe system is applied to the surface of the body part at the withdrawalsite. To “express” the body fluid out of the opening made in the body bymeans of the puncturing device, many systems in the prior art (forexample PCT Patent Publication No. WO 01/89383) comprise a compressionunit with which the internal pressure in the area of the withdrawal siteis increased. The user presses the body part at the withdrawal site ontothe optionally deformable compression unit. He leaves the body part inthis pressed-on state during formation of a skin opening and optionallyalso during collection of the body fluid. A pressure sensor can checkwhether the pressure with which the area of skin is pressed onto thecompression unit is sufficient to collect the body fluid, and, ifappropriate, it can determine the required duration of withdrawal ortake other measures to ensure collection of a sufficient sample volume.If the system for withdrawal of body fluid is used exclusively to createan opening in the skin with the aid of the puncturing device, thepressure sensor can check whether the user is pressing a body part ontoa press-on area of the appliance and is thus indicating his readiness toactivate the puncturing device. However, in contrast to the pressuresensor disclosed in PCT Patent Publication No. WO 02/100254, thepressure sensor according to the invention is not used to automaticallytrigger the puncturing, but only to prepare or adapt the system foroptimal puncturing of the surface of the body part.

In a further embodiment of the present invention, the sensor is aninductive, optical or capacitive proximity sensor for detecting thedistance of the withdrawal site, located on the surface of the bodypart, from a press-on area of the system. The press-on area of thesystem is that area with which the system is pressed onto the surface ofthe body part during withdrawal of body fluid, e.g., a compression unitas mentioned above. The proximity sensor is intended to detect whetherthe body part is situated on the press-on area or at a distance from it,and, as a result, to either release or block the puncturing device.

The evaluation unit of the system according to the invention forwithdrawing body fluid preferably evaluates the variable detected by therespective sensor and then triggers one of the following reactionsdepending on the value of the detected variable:

-   -   blocking or releasing of the at least one puncturing device,    -   setting the puncture depth of the puncturing device selected for        creating the opening in the body,    -   setting the geometric shape of a press-on area of the system for        withdrawing body fluid,    -   setting the cross section of an opening in a press-on area of        the system for withdrawing body fluid, through which opening the        puncturing device can penetrate into the surface of the body        part,    -   selecting one of at least two press-on areas included in the        system for withdrawing body fluid,    -   selecting one of at least two puncturing devices contained in        the system for withdrawing body fluid,    -   setting the duration of the withdrawal procedure,    -   displaying text on a display device, and    -   displaying or setting evaluation parameters which are used by a        device for analyzing the body fluid.

Releasing or blocking of the puncturing device is expedient, forexample, when the variable measured by a pressure sensor, proximitysensor, resistance sensor or conductivity sensor indicates that thewithdrawal site of a body part is located or not located in a positionsuitable for puncturing, for example pressed with sufficient orinsufficient pressure onto a compression unit. In the case of release ofthe puncturing device, the system is ready for activation of thepuncturing device. The puncturing can then be triggered, preferablymanually by the user. Blocking of the puncturing device can also takeplace if a skin temperature sensor detects that the skin temperature isbelow a defined temperature where the blood circulation in the skin isexpected to be inadequate for collecting blood.

The puncture depth of the puncturing device selected for creating theopening in the body can be set on the basis of the variables detected byone of the abovementioned sensors. The puncture depth selected is asshallow as possible in order to substantially avoid pain and scarring ofthe user. The settings preferably range between puncture depths of 0.5and 2 mm. If, for example, the variable detected with a temperaturesensor, position sensor, inclination sensor, resistance sensor orconductivity sensor indicates a puncture site (for example finger, arm,earlobe), the puncture depth can be set so that it is adapted to theconditions at this withdrawal site and so that the desired volume offluid is thus collected. This therefore permits automatic blood samplingat a plurality of sampling sites.

The geometric shape of a press-on area of the system for withdrawingbody fluid can also be set. In this case, the geometric shape is adaptedto the conditions of the withdrawal site. The cross section of anopening in the press-on area of the system for withdrawing body fluid ispreferably set, through which opening the puncturing device canpenetrate into the surface of the body part. For example, in the case ofa cone-shaped press-on area in which the puncturing device is guidedthrough a circular opening onto the body surface, the diameter of thecircular opening varies. With a suitable choice of diameter, thecone-shaped press-on area fits snugly onto the body part, in particularthe finger pad or forearm, during withdrawal of the body fluid. Thevariations in the diameter of the opening can, for example, follow theprinciple of an iris diaphragm. A further possible setting of thegeometric shape of the press-on area involves adjusting the distancebetween two parallel rods acting as a support for the body part.

A further possible reaction of the system for withdrawing body fluid isthe selection of one of at least two press-on areas if, from the atleast one variable detected by the at least one sensor, a conclusion isdrawn regarding the withdrawal location. For example, the system cantrigger an automatic displacement of the different press-on areas on aslide, by which means a selected press-on area adapted to the withdrawalsite is driven into a position in which the system for withdrawing bodyfluid is ready to use the selected press-on area.

The selection of one of at least two puncturing devices contained in thesystem for withdrawing body fluid is also possible. Thus, it is possibleto select and use the puncturing device ideally suited for the selectedwithdrawal site (for example finger, arm) and for the state of thelatter (for example temperature).

A further possible reaction of the system according to the invention forwithdrawing body fluid is the setting of the duration of the withdrawalprocedure, if the system is used not just for puncturing, but also forcollecting blood, for example by pressing blood out of the body openingor collecting it via a cannula. The duration of the withdrawal procedureis the time during which the user is intended to leave the body partapplied to the system, in particular to a press-on area, so as tocollect a sufficient volume of body fluid. The optimal duration forcollecting the volume of body fluid ideal for analysis is, for example,dependent on the skin temperature, on the withdrawal location, inparticular the thickness of the skin there, and on the puncture depth.

Moreover, a text can be displayed on a display device of the system onthe basis of the at least one variable detected by the at least onesensor. This text can, for example, contain a warning which warns theuser against continuing with the withdrawal procedure if the conditionsfor withdrawal of body fluid are unfavorable or unsuitable, for exampleif the skin at the withdrawal site is too cold, or if the body part doesnot lie uniformly or with sufficient pressure on the press-on area, orif the system for withdrawing body fluid has an operating error. It isalso conceivable to display a user menu, for example if, on the basis ofthe variable detected with a sensor, no clear conclusion can be drawnconcerning the location or state of the withdrawal site, so that theuser is requested to input the required information into the system.

Moreover, on the basis of the detected variable, it is possible todisplay or to set evaluation parameters which are used by a device foranalyzing body fluid. Thus, for example, the different composition ofthe body fluid withdrawn at different withdrawal sites (for examplefinger pad or forearm) can be taken into account in the analysis.

In a preferred embodiment of the present invention, the system forwithdrawing body fluid comprises a compression unit for increasing theinternal pressure in the area of the withdrawal site when collecting thebody fluid. This is, for example, a compression unit as is known fromPCT Patent Publication No. WO 01/89383 A2. By using this compressionunit, the so-called milking movement for expressing blood from thepuncture site can be imitated in a way which is simple and convenientfor the user. Not only does the compression unit deliver largerquantities of body fluid than is the case with other press-on devices ofthe prior art; the press-on and withdrawal procedure is also much moreconvenient for the patient. This is due, firstly, to the fact that thecompression unit fits snugly on the body part, in particular a finger.In addition, however, there is also the fact that the compression unitallows sufficient quantities of body fluid to be collected even withvery shallow puncture depths. Another very important advantage of theinvention is that, by using a compression unit with a press-on area madeof deformable material, it is possible to withdraw body fluid reliablyand conveniently from differently shaped body parts. In particular,therefore, body fluid can be withdrawn easily and reliably from fingersof different sizes. In addition, by means of the deformable material, itis possible to compensate for shape differences of the pressed-on bodypart (tip of the finger versus side of the finger). In this way,capillary blood can be collected particularly advantageously from thefinger pad. In addition, it is also possible to withdraw blood orinterstitial fluid from other body parts, for example the arm. Thecompression unit has the effect that the compression of the body partnot only takes place in the direction of the primary contact pressure,but that the contact pressure is also at least partly converted in sucha way that a compression takes place with force components transverse tothe primary contact pressure. The area of the body part at which fluidis to be withdrawn is in this way laterally compressed. By means of thecompression unit, the internal pressure in an area of the body part isincreased. This area of increased internal pressure is adjacent to thearea on which the pressure acts, and it is surrounded by a press-onarea. A puncturing device can puncture the skin at the area of increasedinternal pressure, and body fluid can be withdrawn from here. Thecompression unit includes a press-on area made of a deformable material.Such a material on the one hand makes the withdrawal procedure moreconvenient for the user, and on the other hand it also makes for easieradaptation to differently shaped or differently sized body parts.Examples of materials for the press-on area are deformable plastics suchas elastomers, rubber and the like. However, other compression units arealso conceivable which, in the system according to the invention forwithdrawing body fluid, increase the internal pressure in the area ofthe withdrawal site when collecting the body fluid.

In the system according to the invention for withdrawing body fluid, atleast one sensor is preferably arranged in the press-on area of thesystem. The press-on area is in this case adjacent to the withdrawalsite or surrounds the latter, so that the variable detected with thesensor is detected as close as possible to the withdrawal site, in orderto permit as precise as possible a conclusion concerning the locationand state of the withdrawal site.

The invention further relates to an integrated analysis systemcomprising a system according to the invention for withdrawing bodyfluid from a body part, and a device for analyzing at least one propertyof the body fluid. It is advantageous for there to be a high degree ofautomation if the integrated analysis system is used both for puncturingthe withdrawal site and also for collecting and analyzing the bodyfluid. The integrated analysis system advantageously requires only asmall number of maneuvers on the part of the user. For example, the useronly presses on the compression unit in the press-on area, and all thesubsequent steps including output of the analysis result can proceedautomatically. Devices for analyzing at least one property of the bodyfluid are known in the prior art. Examples of devices which arecommercially available are the blood glucose analysis systems sold underthe name ACCU-CHEK® Compact Plus and ACCU-CHEK® Advantage from RocheDiagnostics Corporation, Indianapolis, Ind.

The system according to the invention for withdrawing body fluid ispreferably used for withdrawing blood or interstitial fluid, preferablyfrom the finger pad or from the forearm. The integrated analysis systemaccording to the invention is preferably used for withdrawing blood orinterstitial fluid and for analyzing the glucose content in the blood orin the interstitial fluid.

Another subject of the present invention is a method for configuring asystem for withdrawing body fluid, which system is used for withdrawingbody fluid from a body part via a withdrawal site, said methodcomprising the steps of measuring at least one variable dependent on thelocation and state of the withdrawal site, and selecting a setting,which is dependent on the value of the measured variable and influencesthe withdrawal of body fluid, in the system for withdrawing body fluid.

By measuring the at least one variable dependent on the location andstate of the withdrawal site, and by the resulting selection of thesetting which influences the withdrawal of the body fluid, the systemfor withdrawing body fluid can be automatically and optimally adapted tothe withdrawal conditions (for example skin temperature, shape of thebody part, thickness of the skin, contact pressure of the body part)before the skin is punctured.

In the method according to the invention, at least one of the followingvariables is preferably measured: temperature, electrical resistance,electrical conductivity, electrical current strength, electricalvoltage, position, inclination, pressure, acceleration, and opticalvariables.

In the method according to the invention, at least one of the followingsettings is preferably selected as a function of the value of themeasured variable:

-   -   blocking or releasing of a puncturing device,    -   setting a puncture depth of a puncturing device selected for        generating the opening in the body,    -   setting a geometric shape of a press-on area of the system for        withdrawing body fluid,    -   setting the cross section of an opening in a press-on area of        the system for withdrawing body fluid, through which opening a        puncturing device can penetrate into the surface of the body        part,    -   selecting one of at least two press-on areas included in the        system for withdrawing body fluid,    -   selecting one of at least two puncturing devices contained in        the system for withdrawing body fluid,    -   setting the duration of the withdrawal procedure,    -   displaying text on a display device, and    -   displaying or setting evaluation parameters which are used by a        system for analyzing body fluid.

As regards the measured variables and the settings as a function of thevalue of the measured variable, the statements made above in relation tothe system according to the invention for withdrawing body fluidlikewise apply to the method according to the invention.

It is also conceivable for the value of the measured variable to bestored on a storage medium using GPS and/or radio-clock information.Thus, for example, a measured value can be stored together with positioncoordinates and clock time, so that this information can be called up ata later time and can be used, for example, for statistical evaluation.

Another subject of the present invention is a method for selecting amenu item from a menu for controlling a system for withdrawing bodyfluid from a body part, said method comprising the steps of

-   -   measuring one of the variables of temperature, electrical        resistance, electrical conductivity, electrical current        strength, electrical voltage, position, inclination, pressure,        acceleration, or optical variables, and selecting the menu item        as a function of the value of the measured variable.

In this way, the user, without pressing a key, is able to make aselection from the menu for controlling the system for withdrawing bodyfluid by means of a sensorily detectable influence of one of thesevariables. For measuring the evaluated variable, a sensor used in themeasurement in step A) of the method according to the invention canlikewise be used to configure a system for withdrawing body fluid. Inthe method according to the invention for selecting a menu item from amenu for controlling a system for withdrawing body fluid, theinclination, position or acceleration, for example, can be measured withthe aid of an inclination sensor, position sensor or accelerationsensor. The user can select the inclination or position, and canaccelerate the system for withdrawing body fluid in a defined direction,in such a way that he gives the measured variable a defined value whichin turn is assigned to a defined menu item in the menu. In this way, theuser can quickly and conveniently make a selection from the menu. Thismakes it possible, for example, to create integrated analysis systems ofhigh efficiency.

It is noted that terms like “preferably”, “commonly”, and “typically”are not utilized herein to limit the scope of the claimed invention orto imply that certain features are critical, essential, or evenimportant to the structure or function of the claimed invention. Rather,these terms are merely intended to highlight alternative or additionalfeatures that may or may not be utilized in a particular embodiment ofthe present invention.

For the purposes of describing and defining the present invention it isnoted that the term “substantially” is utilized herein to represent theinherent degree of uncertainty that may be attributed to anyquantitative comparison, value, measurement, or other representation.The term “substantially” is also utilized herein to represent the degreeby which a quantitative representation may vary from a stated referencewithout resulting in a change in the basic function of the subjectmatter at issue.

Having described the invention in detail and by reference to specificembodiments thereof, it will be apparent that modification andvariations are possible without departing from the scope of theinvention defined in the appended claims. More specifically, althoughsome aspects of the present invention are identified herein as preferredor particularly advantageous, it is contemplated that the presentinvention is not necessarily limited to these preferred aspects of theinvention.

1. A system for withdrawing body fluid from a body part via a withdrawalsite located on the surface of the body part, the system comprising: atleast one sensor for detecting at least one variable dependent on thelocation or state of the withdrawal site; an evaluation unit forevaluating the at least one variable detected by the at least one sensorand for triggering a reaction, dependent on the value of the detectedvariable, in the system for withdrawing body fluid, said reactionserving to prepare the system for the withdrawal of body fluid; and atleast one puncturing device for creating an opening in the body at thewithdrawal site; wherein the system further comprises a compression unitfor increasing the internal pressure in the area of the withdrawal sitein a lateral direction when collecting the body fluid, in such a waythat body fluid is expressed out of the opening.
 2. The system of claim1, wherein the sensor comprises a sensor for detecting at least one ofthe variables of temperature, electrical resistance, electricalconductivity, electrical current strength, electrical voltage, position,inclination, pressure, acceleration, and optical variables.
 3. Thesystem of claim 1, wherein the sensor comprises a temperature sensor fordetecting the skin temperature on the surface of the body part at thewithdrawal site.
 4. The system of claim 1, wherein the sensor comprisesa sensor for detecting the electrical resistance or the electricalconductivity of skin on the surface of the body part at the withdrawalsite.
 5. The system of claim 1, wherein the sensor comprises a positionor inclination sensor for detecting the position or inclination of thesystem upon contact with the withdrawal site.
 6. The system of claim 1,wherein the sensor comprises a pressure sensor for detecting thepressure with which a press-on area of the system is applied to thesurface of the body part at the withdrawal site.
 7. The system of claim1, wherein the sensor comprises an inductive, optical or capacitiveproximity sensor for detecting the distance of the withdrawal site,located on the surface of the body part, from a press-on area of thesystem.
 8. The system of claim 1, wherein the evaluation unit is adaptedto trigger at least one of the following reactions dependent on thevalue of the at least one detected variable: blocking or releasing ofthe at least one puncturing device; setting the puncture depth of thepuncturing device selected for creating the opening in the body; settingthe geometric shape of a press-on area of the system for withdrawingbody fluid; setting the cross section of an opening in a press-on areaof the system for withdrawing body fluid, through which opening thepuncturing device can penetrate into the surface of the body part;selecting one of at least two press-on areas included in the system forwithdrawing body fluid; selecting one of at least two puncturing devicescontained in the system for withdrawing body fluid; setting the durationof the withdrawal procedure; displaying text on a display device; anddisplaying or setting evaluation parameters which are used by a devicefor analyzing the body fluid.
 9. The system of claim 1, wherein at leastone sensor is arranged in a press-on area of the system for withdrawingbody fluid.
 10. An integrated analysis system comprising the system forwithdrawing body fluid from a body part according to claim 1 and adevice for analyzing at least one property of the body fluid.
 11. Theintegrated analysis system of claim 10 wherein the system is adapted forwithdrawing blood or interstitial fluid and for analyzing the glucosecontent in the blood or in the interstitial fluid.